FileSender is an open-source web application for sending files of any size. The sender controls who can download the files and for how long, and the files are deleted automatically after the chosen period. Users authenticate before sending. It was originally created with the needs of scientists and researchers in mind, and instances for research and education are offered by many national research networks and institutes. FileSender is (self-)hosted server software, and service providers can offer it white-label.
FileSender is a programme of The Commons Conservancy, a foundation ("stichting") established under Dutch law, with a board that governs the project. The code is released under the BSD 3-Clause licence, and a new version appeared in September 2026. You can run FileSender on your own servers, in which case uploaded files stay on infrastructure you control, or use an instance operated by an organisation you trust. The maintainer does not run a central hosted service for all users.